1.Technical Field
A method of manufacturing a NAND flash device, is disclosed which can prevent program disturb defects from being generated due to damages of ion implantation processes for controlling wells and a threshold voltage.
2. Discussion of Related Art
An ion implantation process for forming a triple well, an ion implantation process for forming a P well, an ion implantation process for forming an N well, an ion implantation process for controlling a threshold voltage, a process for forming a gate oxide film for a high voltage device in a high voltage device region, a process for forming a tunnel oxide film in a cell region, and a process for forming an element isolation film are sequentially performed before a process for forming a gate of 0.115 μm tech of NAND flash EEPROM. Gate electrodes, namely a floating gate electrode and a control gate electrode are formed on the resulting structure.
However, an annealing process is not at all performed after the ion implantation processes for controlling the wells and the threshold voltage, so that damages of a semiconductor substrate by the ion implantation cannot be cured. Such damages cause dislocation of the semiconductor substrate and generate leakage current paths on the semiconductor substrate, which results in program disturb fail.